Twenty-eight-cornered strengthening member for vehicles

ABSTRACT

A strengthening member for a motor vehicle and a vehicle including a strengthening member are provided. The strengthening member can have a cross-section that has twenty-eight corners and includes sides and corners arranged to create sixteen internal angles and twelve external angles. The strengthening member can have a cross-section that includes a central portion and four lobe portions. The vehicle may include a strengthening member that has twenty-eight corners and includes sides and corners arranged to create sixteen internal angles and twelve external angles.

TECHNICAL FIELD

The present disclosure relates generally to a strengthening member for avehicle body or other structures. The present disclosure relates morespecifically to a strengthening member having a twenty-eight-corneredcross-section and to motor vehicles including a strengthening memberhaving a twenty-eight-cornered cross-section.

BACKGROUND

It is desirable, for vehicle strengthening members, to maximize impactenergy absorption and bending resistance while minimizing mass per unitlength of the strengthening member. Impact energy absorption may bemaximized, for example, by assuring that the strengthening membercompacts substantially along a longitudinal axis of the strengtheningmember upon experiencing an impact along this axis. Such longitudinalcompaction may be referred to as a stable axial crush of thestrengthening member.

When a compressive force is exerted on a strengthening member, forexample, by a force due to a front impact load on a vehicle's front railor other strengthening member in the engine compartment, thestrengthening member can crush in a longitudinal direction to absorb theenergy of the collision. In addition, when a bending force is exerted ona strengthening member, for example, by a force due to a side impactload on a vehicle's front side sill, B-pillar or other strengtheningmember, the strengthening member can bend to absorb the energy of thecollision.

Conventional strengthening members rely on increasing the thickness andhardness of side and/or corner portions to improve crush strength.However, such increased thickness and hardness increases weight of thestrengthening member and reduces manufacturing feasibility. It may bedesirable to provide a strengthening assembly configured to achieve thesame or similar strength increase as provided by the thickened sidesand/or corners, while minimizing mass per unit length of the member, andmaintaining a high manufacturing feasibility.

It may further be desirable to provide a strengthening member that canachieve increased energy absorption and a more stable axial collapsewhen forces such as front and side impact forces are exerted on thestrengthening member, while also conserving mass to reduce vehicleweights and meet emission requirements. Also, it may be desirable toprovide a strengthening member that can achieve improved energyabsorption and bend when a bending force is exerted on the strengtheningmember. Additionally, it may be desirable to provide a strengtheningmember that possesses improved noise-vibration-harshness performance dueto work hardening on its corners. In addition, it may be desirable, toprovide a tunable strengthening member cross-section configured toachieve strength increases (i.e., load carrying and energy absorption)over basic polygonal designs, while also allowing flexibility in designto meet a range of vehicle applications.

SUMMARY

In accordance with various exemplary embodiments of the presentdisclosure, a strengthening member for a motor vehicle is provided. Thestrengthening member has a cross-section including twenty-eight cornersand including sides arranged to create sixteen internal angles andtwelve external angles.

In accordance with another aspect of the present disclosure, astrengthening member for a motor vehicle is provided. The strengtheningmember has a cross-section including twenty-eight corners and includingtwenty-eight sides arranged to create internal angles and externalangles. The corners of the cross-section are defined by angles thatalternate between four consecutive internal angles and three consecutiveexternal angles.

In accordance with another aspect of the present disclosure, a motorvehicle is provided. The vehicle includes a strengthening member. Thestrengthening member has a cross-section including twenty-eight cornersand including sides arranged to create sixteen internal angles andtwelve external angles.

In accordance with another aspect of the present disclosure,strengthening member for a motor vehicle is provided. The strengtheningmember has twenty-eight sides and twenty-eight corners. A cross-sectionof the strengthening member includes a central portion and four lobeportions.

Additional objects and advantages will be set forth in part in thedescription which follows, and in part will be obvious from thedescription, or may be learned by practice of the present teachings. Theobjects and advantages of the present disclosure will be realized andattained by means of the elements and combinations particularly pointedout in the appended claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the claimed subject matter. The accompanyingdrawings, which are incorporated in and constitute part of thisspecification, illustrate exemplary embodiments of the presentdisclosure and together with the description, serve to explainprinciples of the present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

At least some features and advantages of the present teachings will beapparent from the following detailed description of exemplaryembodiments consistent therewith, which description should be consideredwith reference to the accompanying drawings, wherein:

FIG. 1A illustrates a cross-section of a strengthening member havingtwenty-eight-cornered cross-section including sixteen internal anglesand twelve external angles in accordance with the present teachings;

FIG. 1B illustrates the cross-section of a strengthening member havingtwenty-eight-cornered cross-section including sixteen internal anglesand twelve external angles, as shown in FIG. 1A, and with variouslengths, thicknesses, and angles identified;

FIGS. 2A-2B illustrate top and perspective views of a first exemplaryembodiment of a strengthening member having a twenty-eight-corneredcross-section with sixteen internal angles and twelve external angles,as shown in FIG. 1A;

FIGS. 3A-3B illustrate top and perspective views of a second exemplaryembodiment of a strengthening member having a twenty-eight-corneredcross-section with sixteen internal angles and twelve external angles inaccordance with the present teachings;

FIGS. 4A-4B illustrate top and perspective views of a third exemplaryembodiment of a strengthening member having a twenty-eight-corneredcross-section with sixteen internal angles and twelve external angles inaccordance with the present teachings;

FIGS. 5A-5B illustrate top and perspective views of a fourth exemplaryembodiment of a strengthening member having a twenty-eight-corneredcross-section with sixteen internal angles and twelve external angles inaccordance with the present teachings;

FIGS. 6A-6B illustrate top and perspective views of a fifth exemplaryembodiment of a strengthening member having a twenty-eight-corneredcross-section with sixteen internal angles and twelve external angles inaccordance with the present teachings;

FIGS. 7A-7B illustrate top and perspective views of a sixth exemplaryembodiment of a strengthening member having a twenty-eight-corneredcross-section with sixteen internal angles and twelve external angles inaccordance with the present teachings;

FIGS. 8A-8B illustrate top and perspective views of a seventh exemplaryembodiment of a strengthening member having twenty-eight-cornered crosssections with sixteen internal angles and twelve external angles inaccordance with the present teachings;

FIG. 9 illustrates strengthening members of various cross-sectionshaving substantially the same thickness, substantially the longitudinallength, and cross-sectional dimensions along perpendicularly orientedtransverse axes with substantially the same lengths;

FIG. 10 illustrates an exemplary quasi-static axial collapse of thestrengthening members shown in FIG. 9;

FIG. 11 illustrates an exemplary dynamic crush of the strengtheningmembers shown in FIG. 9;

FIG. 12 is a graph of the dynamic crush force and associated crushdistance for the exemplary strengthening members shown in FIG. 9;

FIG. 13 is a graph of the dynamic axial crush energy and associatedaxial crush distance for the exemplary strengthening members shown inFIG. 9;

FIG. 14 illustrates an exemplary embodiment of a vehicle frame withseveral components for which a strengthening member having atwenty-eight-cornered cross-section with sixteen internal angles andtwelve external angles can be used; and

FIG. 15 illustrates an exemplary embodiment of a vehicle upper body withseveral components for which a strengthening member having atwenty-eight-cornered cross-section with sixteen internal angles andtwelve external angles can be used.

Although the following detailed description makes reference to exemplaryillustrative embodiments, many alternatives, modifications, andvariations thereof will be apparent to those skilled in the art.Accordingly, it is intended that the claimed subject matter be viewedbroadly.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made in detail to various exemplary embodiments,examples of which are illustrated in the accompanying drawings. Thevarious exemplary embodiments are not intended to limit the disclosure.To the contrary, the disclosure is intended to cover alternatives,modifications, and equivalents of the exemplary embodiments. In thedrawings and the description, similar elements are provided with similarreference numerals. It is to be noted that the features explainedindividually in the description can be mutually combined in anytechnically expedient manner and disclose additional embodiments of thepresent disclosure.

The present teachings contemplate strengthening members withtwenty-eight-cornered cross-sections having substantially increasedstiffness throughout the sides and corners without increasing thicknesswithin the corners as done in conventional strengthening members. Thestrengthening members of the present disclosure are designed based inpart on, for example, a variety of tunable parameters configured toachieve strength increases (i.e., load carrying and energy absorption)over basic polygonal designs (e.g., polygonal strengthening member crosssections having less or the same number of sides), while also allowingdesign flexibility to meet a range of vehicle applications.

In accordance with the present teachings, the shape of the strengtheningmembers disclosed herein provides the strengthening member withstabilized folding, reduced crush distance, and increased energyabsorption in response to an axially applied crash force. In at leastsome embodiments, the shape also improves moisture shedding abilities ofthe strengthening member and permits a more customized fit with othervehicle components.

The strengthening members in accordance with the present teachings canachieve increased energy absorption and a more stable axial collapsewhen forces such as front and side impact forces are exerted on thestrengthening member. Furthermore, the side lengths and configurations,and/or degrees of the internal and external angles, of the strengtheningmembers in accordance with the present teachings can achieve a similar,if not greater, strength increase as thickened corners, while minimizingmass per unit length of the member and maintaining a high manufacturingfeasibility because the member can be formed by stamping, bending, pressforming, hydro-forming, molding, casting, extrusion, uniform ornon-uniform roll forming, machining, forging, and/or other knownmanufacturing processes. Thus-formed sections can be joined via welding,brazing, soldering, adhesive bonding, fastening, press fitting or otherknown joining technologies.

Strengthening members in accordance with the present teachings cancomprise, for example, steel alloys, titanium alloys, aluminum alloys,magnesium alloys, nylons, plastics, polymers, composites,fiber-reinforced composites, hybrid materials (i.e., multiple dissimilarmaterials), shape-memory materials, foams, gels or any other suitablematerials. Those of ordinary skill in the art would understand, forexample, that the material used for a strengthening member may be chosenbased at least in part on intended application, strength/weightconsiderations, cost, packaging space, and/or other design factors.

An exemplary embodiment of a cross-section of a strengthening member 100having twenty-eight corners in accordance with the present teachings isillustrated in FIG. 1A. The strengthening member 100 has twenty-eightsides S₁-S₂₈. The cross-section of the strengthening member inaccordance with the present teachings may include a central portion andfour lobe portions. The central portion may be defined by eight of thesides, for example, sides S₂, S₃, S₉, S₁₀, S₁₆, S₁₇, S₂₃, and S₂₄ definea central portion of the cross-section of strengthening member 100. Eachlobe portion may be defined by five of the sides, for example, sidesS₄-S₈ define a first lobe portion, sides S₁₁-S₁₅ define a second lobeportion, sides S₁₈-S₂₂ define a third lobe portion, and sides S₁ andS₂₅-S₂₈ define a fourth lobe portion of the cross-section ofstrengthening member 100.

As labeled in FIG. 1B, the illustrated cross-section of thestrengthening member 100 comprises twenty-eight sides S₁-S₂₈ havingcross-sectional lengths L₁-L₂₈ and cross-sectional thicknesses T₁-T₂₈,sixteen internal corners with cross-sectional angles Θ_(i1)-Θ_(i16), andtwelve external corners with cross-sectional angles Θ_(e1)-Θ_(e12).

The perimeter of the twenty-eight-sided cross-section generally forms apolygon comprising a plurality of internal and external corners. Asembodied herein and shown in FIGS. 1A-1B, the polygon may be formed ofalternating internal and external angles, and in particular, may beformed by alternating four consecutive internal corners/angles withthree consecutive external corners/angles. This repeating pattern, whichalternates between four consecutive internal corners/angles and threeconsecutive external corners/angles (i.e., an alternatingfour-in-three-out configuration), results in a cross-section with up tofour bisecting planes of symmetry. Under an axial and symmetric loadingcondition, strengthening members with symmetrical, polygonalcross-sections, including the various embodiments of the presentteachings, may have better load carrying capabilities and energyabsorbing capabilities than those with asymmetrical, polygonal crosssections with an equivalent number of corners and sides. Furthermore,strengthening members with symmetrical, polygonal cross-sections withmore than two bisecting planes of symmetry (e.g., three bisecting planesof symmetry, four bisecting planes of symmetry, or five or morebisecting planes of symmetry), including the various embodiments of thepresent teachings, may have better load carrying capabilities and energyabsorbing capabilities than those with symmetrical, polygonal crosssections with two or fewer bisecting planes of symmetry and anequivalent number of corners and sides. For example, the exemplarycross-section shown in FIG. 1 has four bisecting planes of symmetry.However, as those of ordinary skill in the art will understand, use ofasymmetrical cross-sections may offer other benefits that provideadvantages that cannot be realized using a symmetrical cross-section.The present disclosure contemplates that a twenty-eight-sided,twenty-eight-cornered cross-section, in accordance with the presentteachings, may be either symmetrical or asymmetrical.

Depending upon the particular application and/or the desired features ofthe strengthening member, the cross-sectional lengths of the sides andthe cross-sectional thicknesses of the sides of the twenty-eight-sided,twenty-eight-cornered strengthening member as well as the internal andexternal corner angles of the strengthening member can be varied (i.e.,can be tuned) to achieve improved strength and other performancefeatures (e.g., stability of folding pattern) compared to conventionalstrengthening member cross-sections. Varying these features of thetwenty-eight-sided, twenty-eight-cornered strengthening member mayobviate the need for increased side and/or corner thickness. Inaccordance with various exemplary embodiments of the present teachings,the cross-sectional lengths L₁-L₂₈ of sides S₁-S₂₈, the cross-sectionalthicknesses T₁-T₂₈ of the sides as well as the cross-sectional internalangles Θ_(i1)-Θ_(i16) of internal corners and external anglesΘ_(e1)-Θ_(e12) of the external corners can be varied to a certaindegree, as would be understood by one skilled in the art, for example inaccordance with available packaging space within a vehicle.

In addition, in a strengthening member in accordance with the presentteachings, each internal corner angle Θ_(i1)-Θ_(i16) of a cross-sectionof the strengthening member can range from about 30° to about 175°, andeach external corner angle Θ_(e1)-Θ_(e12) of a cross-section of thestrengthening member can range from about 45° to about 175°. Inaccordance with the present teachings, the internal anglesΘ_(i1)-Θ_(i16) of a cross-section of the strengthening member may all besubstantially the same, and/or, the external angles Θ_(e1)-Θ_(e12) of across-section of the strengthening member may all be substantially thesame. Additionally, the present teachings contemplate embodiments forwhich one or more of the internal angles Θ_(i1)-Θ_(i16) are right anglesas well as embodiments for which one or more than one of the externalangles Θ_(e1)-Θ_(e16) are right angles. Additionally or alternatively,the present disclosure contemplates embodiments in which at least someof the internal angles Θ_(i1)-Θ_(i16) of a cross-section of thestrengthening member differ from one another, and similarly, at leastsome of the external angles Θ_(e1)-Θ_(e12) of a cross-section of thestrengthening member differ from one another. FIG. 1B illustrates anexemplary cross-section in which internal angles Θ_(i1), Θ_(i4), Θ_(i5),Θ_(i8), Θ_(i9), Θ_(i12), Θ_(i13), and Θ_(i16) are about 90°; internalangles Θ_(i2), Θ_(i7), Θ_(i10), and Θ_(i15) are about 138°; internalangles Θ_(i3), Θ_(i6), Θ_(i11), and Θ_(i14) are about 132°, externalcorner angles Θ_(e1), Θ_(e3), Θ_(e4), Θ_(e6), Θ_(e7), Θ_(e9), Θ_(e10),and Θ_(e12) are about 102°; external corner angles Θ_(e2), Θ_(e5),Θ_(e8), and Θ_(e11) are about 156°; and the aspect ratio is about 1:1.

In certain exemplary embodiments of the present disclosure, such as inan automotive application, for example, a cross-sectional length L₁-L₂₈of each side S₁-S₂₈ of a cross-section of the strengthening member canrange from about 10 mm to about 250 mm. In other exemplary embodiments,such as in an aircraft, spacecraft, watercraft, or building application,for example, a cross-sectional length L₁-L₂₈ of each side S₁-S₂₈ of thecross-section of the strengthening member may be larger. FIG. 1Billustrates an exemplary cross-section in which cross-sectional lengthsL₁, L₄, L₈, L₁₁, L₁₅, L₁₈, L₂₂, and L₂₅ of sides S₁, S₄, S₈, S₁₁, S₁₅,S₁₈, S₂₂, and S₂₅ are each a first length, e.g., 27 mm; cross-sectionallengths L₂, L₃, L₉, L₁₀, L₁₆, L₁₇, L₂₃, and L₂₄ of sides S₂, S₃, S₉,S₁₀, S₁₆, S₁₇, S₂₃, and S₂₄ are each a second length, e.g., 22 mm;cross-sectional lengths L₅, L₇, L₁₂, L₁₄, L₁₉, L₂₁, L₂₆, and L₂₈ ofsides S₅, S₇, S₁₂, S₁₄, S₁₉, S₂₁, S₂₆, and S₂₈ are each a third length,e.g., 22 mm; and cross-sectional lengths L₆, L₁₃, L₂₀, and L₂₇ of sidesS₆, S₁₃, S₂₀, and S₂₇ are each a fourth length, e.g., 35 mm.

In certain exemplary embodiments of the present disclosure, such as inan automotive application, for example, a thickness T₁-T₂₈ of the sidesof the cross-section of the strengthening member can range from about0.6 mm to about 6.0 mm. In other exemplary embodiments of thestrengthening member, such as in an aircraft, spacecraft, watercraft, orbuilding application, for example, a thickness T₁-T₂₈ of the sides of across-section of the strengthening member may be larger. In oneexemplary embodiment, a cross-sectional thickness T₁-T₂₈ of each of thesides of the strengthening member may be about 3.3 mm. In anotherexemplary embodiment, a cross-sectional thickness T₁-T₂₈ of each of thesides may be about 2.3 mm. In another exemplary embodiment, across-sectional thickness T₁-T₂₈ of each of the sides may be about 2.0mm. In some exemplary embodiments, the cross-sectional thickness T₁-T₂₈of the sides is substantially the same as the thickness of the cornersfor each side. In some exemplary embodiments the cross-sectionalthickness T₁-T₂₈ of each side wall, (e.g., side walls S₂₀₁-S₂₂₈ (seeFIG. 2A)), can vary with respect to each other side wall. Alternativelyor concurrently, the cross-sectional thickness T₁-T₂₈ can vary along therespective cross-sectional lengths L₁-L₂₈ of the sides S₁-S₂₈.

Top and perspective views of a first exemplary embodiment of astrengthening member 200 having a twenty-eight-cornered cross-section,with sixteen internal angles and twelve external angles are illustratedin FIGS. 2A-2B, respectively. Strengthening member 200 has twenty-eightcorners C_(i201)-C_(i216) and C_(e201)-C_(e212), and twenty-eight sidewalls S₂₀₁-S₂₂₈. Sixteen of the corners are internal angle cornersC_(i201)-C_(i216) and twelve of the corners are external angle cornersC_(e201)-C_(e212). Strengthening member 200 also has a first transverseaxis 230, a second transverse axis 240, and a longitudinal axis 250.Although shown with its longitudinal axis 250 positioned substantiallyvertically, when strengthening member 200 (as well as all of the othervarious embodiments in accordance with the present teachings) isinstalled within a vehicle, the longitudinal axis 250 of thestrengthening member may be oriented substantially horizontally.

The strengthening member 200 of FIGS. 2A-2B also has a uniform crosssection along a length of the strengthening member 200, from a first end260 to a second end 270 of the strengthening member 200. Additionally,the longitudinal length LL₂₀₀ of each side S₂₀₁-S₂₂₈ is approximatelythe same, as illustrated in FIGS. 2A-2B. As also illustrated, for allcross-sections, each of eight of the internal angles are substantiallythe same, each of the other eight internal angles are substantially thesame, eight of the external angles are substantially the same, and fourof the other external angles are substantially the same. In particular,each of eight of the internal angles Θ_(i201), Θ_(i204), Θ_(i205),Θ_(i208), Θ_(i209), Θ_(i212), Θ_(i213), and Θ_(i216) are about 90°; eachof the other eight internal angles Θ_(i202), Θ_(i203), Θ_(i206),Θ_(i207), Θ_(i210), Θ_(i211), Θ_(i214), and Θ_(i215) are about 135°;eight of the external angles Θ_(e201), Θ_(e203), Θ_(e204), Θ_(e206),Θ_(e207), Θ_(e209), Θ_(e210), and Θ_(e212) are 102°; and four of theother external angles Θ_(e202), Θ_(e205), Θ_(e208), and Θ_(e211) areabout 156°. The thicknesses of each sidewall S₂₀₁-S₂₂₈ are alsosubstantially the same.

Top and perspective views of an alternative exemplary embodiment of astrengthening member 300 having a twenty-eight-cornered cross-section,with sixteen internal angles and twelve external angles, are illustratedin FIGS. 3A-3B, respectively. The cross-section of the strengtheningmember 300 includes a central portion and four lobe portions. Thecentral portion is defined by eight of the sides, for example, sidesS₃₀₂, S₃₀₃, S₃₀₉, S₃₁₀, S₃₁₆, S₃₁₇, S₃₂₃, and S₃₂₄ define a centralportion of the cross-section of strengthening member 300. Each lobeportion may be defined by five of the sides, for example, sidesS₃₀₄-S₃₀₈ define a first lobe portion, sides S₃₁₁-S₃₁₅ define a secondlobe portion, sides S₃₁₈-S₃₂₂ define a third lobe portion, and sidesS₃₀₁ and S₃₂₅-S₃₂₈ define a fourth lobe portion of the cross-section ofstrengthening member 300.

Strengthening member 300 differs from strengthening member 200 inseveral aspects. For example, as shown in FIGS. 3A and 3B, one or moreof the side walls of the strengthening member may be angled with respectto the longitudinal axis 350 of the strengthening member to provide ataper to at least a portion of the shape of the strengthening member300. As shown in FIGS. 3A-3B, strengthening member 300 is tapered alongits length, from a first end 360 of the strengthening member 300 to asecond end 370 of the strengthening member. The strengthening member 300tapers along its length at an angle α, which can range from about 1° toabout 65°. The degree of taper of each side wall may be substantiallythe same, or different side walls may exhibit differing degrees oftaper. Tapering may be required due to component packaging constraintsand/or to effectively couple, attach or otherwise bond other componentsto a strengthening member.

In the exemplary embodiment of FIGS. 3A-3B, each of eight of theinternal angles are about 90°, each of the other eight internal anglesare about 135°, eight of the external angles are about 102, and four ofthe other external angles are about 156°. Also, as shown in FIGS. 3A-3B,strengthening member 300 includes recessed areas 334, 335, 336 and 337.Each recessed area 334, 335, 336 and 337 extends along the length of thestrengthening member 300 from first end 360 to second end 370. A side ofthe central portion and two of the lobe portions define each recessalong a length of the strengthening member 300.

In the disclosed exemplary embodiment of FIGS. 3A-3B, thecross-sectional lengths of each of the twenty-eight sides are eachapproximately the same as the cross-sectional lengths of other sideswhen taken at any cross-section along the longitudinal length of thestrengthening member 300. However, the cross-sectional length of eachside gradually/incrementally increases along the longitudinal axis 350of the strengthening member 300 from first end 360 to second end 370 toprovide the tapered shape. As noted above, the embodiment of FIGS. 3A-3Bis exemplary, and therefore all of the contemplated embodiments withvariations to the cross-sectional lengths and thicknesses of the sides,and to the angles of the internal and external corner angles of thetwenty-eight-cornered cross-sections, with sixteen internal angles andtwelve external angles, of the strengthening members in accordance withthe present teachings are not shown in the figures, but based on theteachings herein, will be apparent to those of skill in the art.

Top and perspective views of an alternative exemplary embodiment of astrengthening member 400 having the twenty-eight-cornered cross section,with sixteen internal angles and twelve external angles, are illustratedin FIGS. 4A-4B, respectively. The cross-section of the strengtheningmember 400 includes a central portion and four lobe portions. Thecentral portion is defined by eight of the sides, for example, sidesS₄₀₂, S₄₀₃, S₄₀₉, S₄₁₀, S₄₁₆, S₄₁₇, S₄₂₃, and S₄₂₄ define a centralportion of the cross-section of strengthening member 400. Each lobeportion may be defined by five of the sides, for example, sidesS₄₀₄-S₄₀₈ define a first lobe portion, sides S₄₁₁-S₄₁₅ define a secondlobe portion, sides S₄₁₈-S₄₂₂ define a third lobe portion, and sidesS₄₀₁ and S₄₂₅-S₄₂₈ define a fourth lobe portion of the cross-section ofstrengthening member 400.

Similar to the strengthening member 200, strengthening member 400 has auniform cross-section along a length of the strengthening member 400,from a first end 460 to a second end 470 of the strengthening member400. However, as shown in FIGS. 4A-4B, strengthening member 400 differsfrom strengthening members 200 and 300 in that thedimension-to-dimension ratio of the cross section of the strengtheningmember, taken along transverse axes 430, 440 is not 1:1; rather, theaspect ratio is about 7:10. FIGS. 4A-4B illustrate a strengtheningmember that has a first length 480 along a first (minor) transverse axis430 and a second length 490 along a second (major) transverse axis 440,where the second transverse axis 440 is perpendicular to the firsttransverse axis 430. The aspect ratio of a strengthening member may bedefined as [first length 480]:[second length 490]. In the exemplaryembodiment of FIGS. 4A-4B, the internal corner angles Θ_(i401),Θ_(i404), Θ_(i405), Θ_(i408), Θ_(i409), Θ_(i412), Θ_(i413), and Θ_(i416)are not all same and internal corner angles Θ_(i402), Θ_(i403),Θ_(i406), Θ_(i407), Θ_(i410), Θ_(i411), Θ_(i414), and Θ_(i415) are notall the same. In particular, as shown in FIG. 4A, internal anglesΘ_(i401), Θ_(i408), Θ_(i409), and Θ_(i416) have a first measurement,e.g., of about 90°; internal angles Θ_(i404), Θ_(i405), Θ_(i412), andΘ_(i413) have a second measurement, e.g., of about 90°; internal anglesΘ_(i402), Θ_(i407), Θ_(i410), and Θ_(i415) have a third measurement,e.g., of about 145°; and internal angles Θ_(i403), Θ_(i406), Θ_(i411),and Θ_(i414) have a fourth measurement, e.g., of about 125°.Additionally, the external angles are not all same. In particular, asshown in FIG. 4A, the external angles Θ_(e401), Θ_(e403), Θ_(e407),Θ_(e409), have a first measurement, e.g., of about 98°; external anglesΘ_(e404), Θ_(e406), Θ_(e410), and Θ_(e412) have a second measurement,e.g., of about 106°; external angles Θ_(e402) and Θ_(e408) have a thirdmeasurement, e.g., of about 164°; and external angles Θ_(e405) andΘ_(e411) have a fourth measurement, e.g., of about 148°. As also shown,the sides of the strengthening member 400 have differing cross-sectionallengths. In addition, the strengthening member 400 of the exemplaryembodiment shown in FIGS. 4A-4B includes recessed areas 434, 435, 436and 437 spaced around the perimeter of the strengthening member andextending along the length of the strengthening member 400, eachrecessed area 434-437 extending from first end 460 to second end 470 ofstrengthening member 400. A side of the central portion and two of thelobe portions define each recess along a length of the strengtheningmember 400. As noted above, the embodiment of FIGS. 4A-4B is exemplary,and therefore all of the contemplated embodiments with variations to thecross-sectional lengths of the sides, thicknesses of the sides, theangles of the internal and external corner angles, and the aspect ratioof the twenty-eight-cornered cross-sections, with sixteen internalangles and twelve external angles, of the strengthening members inaccordance with the present teachings are not shown in the figures.

Top and perspective views of an alternative exemplary embodiment of astrengthening member 500 having the twenty-eight-cornered cross-section,with sixteen internal angles and twelve external angles, are illustratedin FIGS. 5A-5B, respectively. The cross-section of the strengtheningmember 500 includes a central portion and four lobe portions. Thecentral portion is defined by eight of the sides, for example, sidesS₅₀₂, S₅₀₃, S₅₀₉, S₅₁₀, S₅₁₆, S₅₁₇, S₅₂₃, and S₅₂₄ define a centralportion of the cross-section of strengthening member 500. Each lobeportion may be defined by five of the sides, for example, sidesS₅₀₄-S₅₀₈ define a first lobe portion, sides S₅₁₁-S₅₁₅ define a secondlobe portion, sides S₅₁₈-S₅₂₂ define a third lobe portion, and sidesS₅₀₁ and S₅₂₅-S₅₂₈ define a fourth lobe portion of the cross-section ofstrengthening member 500.

Similar to the strengthening member 300, strengthening member 500 tapersalong its longitudinal axis 550 from a first end 560 of thestrengthening member to a second end 570 of the strengthening member500. The strengthening member 500 tapers along its length at an angle α,which can range from about 1° to about 65°. In the exemplary embodimentof FIGS. 5A-5B, each of eight of the internal angles are about 90°, eachof the other eight internal angles are about 135°, eight of the externalangles are about 101°, and four of the other external angles are about158°. The cross-sectional thicknesses of each sidewall S₅₀₁-S₅₂₈ arealso substantially the same.

As illustrated in FIG. 5A, the cross-sectional length of side wallsS₅₀₁, S₅₀₄, S₅₀₈, S₅₁₁, S₅₁₅, S₅₁₈, S₅₂₂, and S₅₂₅ are small relative tothe cross-sectional lengths of the rest of the of the side walls, andexternal angles Θ_(e502), Θ_(e505), Θ_(e508), and Θ_(e511) are largerelative to the rest of the external angles and internal angles. Thisdifference in the lengths of the sides provides recessed areas 534, 535,536 and 537, each of which extends along the length of the strengtheningmember 500 from first end 560 to second end 570 of the strengtheningmember. A side of the central portion and two of the lobe portionsdefine each recess along a length of the strengthening member 500. Theserecessed areas 534-537 each have a depth δ₅₃₃-δ₅₃₇, which is decreased(and may be considered relatively shallow) in comparison to the recessedareas shown in the strengthening members illustrated in FIGS. 2A-4B.This type of parameter tuning, i.e., changing the cross-sectionallengths of the sides and external angles to decrease the depth of therecess areas 534-537, can further increase the internal volume of thestrengthening member 500, thereby providing more internal space forother vehicle components. In particular, the combination of thedecreased depth and the modified external angles of the recessed areawork together to increase the total volume of the strengthening member,thereby increasing the space inside the strengthening member in whichother vehicle components may be permanently, temporarily or periodicallyfitted, located, or otherwise disposed. Such vehicle components mayinclude, for example, brake line(s), pipe(s), electric wire(s),cable(s), and/or seatbelt(s). Disposition of the vehicle componentswithin the completely enclosed side walls of the strengthening memberfunction as a shelter to protect the other vehicle components from beingdamaged, for example, during vehicle impact events.

Top and perspective views of an alternative exemplary embodiment of astrengthening member 600 having the twenty-eight-cornered cross-section,with sixteen internal angles and twelve external angles, are illustratedin FIGS. 6A-6B, respectively. The cross-section of the strengtheningmember 600 includes a central portion and four lobe portions. Thecentral portion is defined by eight of the sides, for example, sidesS₆₀₂, S₆₀₃, S₆₀₉, S₆₁₀, S₆₁₆, S₆₁₇, S₆₂₃, and S₆₂₄ define a centralportion of the cross-section of strengthening member 600. Each lobeportion may be defined by five of the sides, for example, sidesS₆₀₄-S₆₀₈ define a first lobe portion, sides S₆₁₁-S₆₁₅ define a secondlobe portion, sides S₆₁₈-S₆₂₂ define a third lobe portion, and sidesS₆₀₁ and S₆₂₅-S₆₂₈ define a fourth lobe portion of the cross-section ofstrengthening member 600. Strengthening member 600 exemplifies that thecross-sectional length of each of the sides of a lobe portion may be thesame, for example, sides S₆₀₄-S₆₀₈, which define a first lobe portion,have the same cross-sectional lengths. Moreover, strengthening member600 exemplifies that the cross-sectional length of each of the sides ofall of the lobe portions may be the same, for example, sides S₆₀₄-S₆₀₈,S₆₁₁-S₆₁₅, S₆₁₈-S₆₂₂, S₆₀₁, and S₆₂₅-S₆₂₈ have the same cross-sectionallengths. Additionally, strengthening member 600 exemplifies that thecross-sectional length of each of the sides defining the centralportions may be the same, for example, sides S₆₀₂, S₆₀₃, S₆₀₉, S₆₁₀,S₆₁₆, S₆₁₇, S₆₂₃, and S₆₂₄ have the same cross-sectional lengths.

Similar to the strengthening members 300 and 500, strengthening member600 tapers along its longitudinal axis 650 from a first end 660 of thestrengthening member to a second end 670 of the strengthening member600. The strengthening member 600 tapers along its length at an angle α,which can range from about 1° to about 65°. In the exemplary embodimentof FIGS. 6A-6B, each of eight of the internal angles are about 90°, eachof the other eight internal angles are about 135°, eight of the externalangles are about 136°, and four of the other external angles are about88°. By virtue of this configuration of the angles, the central portionof each cross-section of the strengthening member 600 has an X-shape.Accordingly, sides S₆₀₂, S₆₁₀, S₆₁₆, and S₆₂₄ are parallel to eachother, and sides S₆₀₃, S₆₀₉, S₆₁₇, and S₆₂₃ are parallel to each other.Further, sides S₆₀₂ and S₆₁₀ are coplanar, sides S₆₁₆, and S₆₂₄ arecoplanar, sides S₆₀₃ and S₆₂₃ are coplanar, and sides S₆₀₉, and S₆₁₇ arecoplanar. The thickness of each sidewall S₆₀₁-S₆₂₈ is also substantiallythe same to each other side wall S₆₀₁-S₆₂₈ and throughout thelongitudinal length of each side wall S₆₀₁-S₆₂₈.

As shown in FIGS. 6A-6B, strengthening member 600 differs fromstrengthening member 500 in that the cross-sectional length of sidewalls S₆₀₁, S₆₀₄, S₆₀₈, S₆₁₁, S₆₁₅, S₆₁₈, S₆₂₂, and S₆₂₅ ofstrengthening member 600 is larger relative to the cross-sectionallength of side walls S₅₀₁, S₅₀₄, S₅₀₈, S₅₁₁, S₅₁₅, S₅₁₈, S₅₂₂, and S₅₂₅of strengthening member 500. Additionally, external angles Θ_(e602),Θ_(e605), Θ_(e608), and Θ_(e611) of strengthening member 600 are smallerrelative external angles Θ_(e502), Θ_(e505), Θ_(e508), and Θ_(e511) ofstrengthening member 500. In part, the sides S₆₀₁, S₆₀₄, S₆₀₈, S₆₁₁,S₆₁₅, S₆₁₈, S₆₂₂, and S₆₂₅, and external angles Θ_(e602), Θ_(e605),Θ_(e608), and Θ_(e611), define recessed areas 634, 635, 636 and 637,each of which extends along the length of the strengthening member 600from first end 660 to second end 670 of the strengthening member. A sideof the central portion and two of the lobe portions define each recessalong a length of the strengthening member 600. These recessed areas634-637 each have a depth δ₆₃₄-δ₆₃₇, which is increased (and may beconsidered relatively deep) in comparison to the recessed areas shown inthe strengthening members illustrated in FIGS. 2A-5B. This type ofparameter tuning, i.e., changing the cross-sectional lengths of thesides and the size of external angles to increase the depth of therecess areas 634-637, can further decrease the internal volume of thestrengthening member 500, thereby providing more external space forother vehicle components. In particular, the combination of theincreased depth and the modified external angles of the recessed areawork together to decrease the total volume of the strengthening member,thereby increasing the space outside the strengthening member in whichother vehicle components may be permanently, temporarily or periodicallyfitted, located, or otherwise disposed. Such vehicle components mayinclude, for example, brake line(s), pipe(s), electric wire(s),cable(s), and/or seatbelt(s). The side walls defining the recessed areacan function as a shelter to protect the other vehicle components frombeing damaged, for example, during vehicle impact events; however, thecomponents remain accessible by virtue of their disposition outside thestrengthening member, thereby improving the feasibility of repair and/orreplacement of the components.

Top and perspective views of an alternative exemplary embodiment of astrengthening member 700 having a twenty-eight-cornered cross-section,with sixteen internal angles and twelve external angles, are illustratedin FIGS. 7A-7B, respectively. Strengthening member 700 has twenty-eightcorners C_(i701)-C_(i716) and C_(e701)-C_(e712), and twenty-eight sidewalls S₇₀₁-S₇₂₈. Sixteen of the corners are internal angle cornersC_(i701)-C_(i716) and twelve of the corners are external angle cornersC_(e701)-C_(e712). Strengthening member 700 also has a first transverseaxis 730, a second transverse axis 740, and a longitudinal axis 750.Although shown with its longitudinal axis 750 positioned substantiallyvertically, when strengthening member 700 (as well as all of the othervarious embodiments in accordance with the present teachings) isinstalled within a vehicle, the longitudinal axis 750 of thestrengthening member may be oriented substantially horizontally. In thisposition, first transverse axis 730 may be oriented substantiallyhorizontally and second transverse axis 740 may be orientedsubstantially vertically, as shown in FIG. 7A. When installed in such aposition, the shape of strengthening member 700 facilitates reducing orpreventing moisture collecting or pooling along portions of the walls ofthe strengthening member. For example, certain conventionalstrengthening members whose walls form adjacent external angles of 90degrees or form rectangular, square, or U-shaped recesses or depressionsmay collect moisture or permit moisture to pool in the recesses,increasing the possibility of weakening of the strengthening member viarusting, stripping, cracking, etc. (i.e., any form of oxidation or otherchemical or physical distortion which the material of manufacture of thestrengthening member may be more susceptible to due to the presence ofmoisture).

In contrast, a strengthening member 700 does not include a recessedportion in which liquids or moisture remain for a long period of time.In particular, each of the internal angles Θ_(i701)-Θ_(i716) andexternal angles Θ_(e701)-Θ_(e712) have been selected such the walls ofthe strengthening member are angled relative to one another to promoteshedding of any moisture or fluid that falls within any recessed portionof the strengthening member. For example, as shown in FIGS. 7A and 7B,strengthening member 700 includes a first recessed portion 734 definedby side walls S₇₀₁, S₇₀₂, S₇₀₃, and S₇₀₄. Internal angles Θ_(i701),Θ_(i702), Θ_(i715), and Θ_(i716) are obtuse, and external anglesΘ_(e701), Θ_(e702), and Θ_(e703) are obtuse. As a result, side wallsS₇₂₈ and S₇₀₁-S₇₀₅ are sloped/angled side walls in such a manner thatfluid impinging or collecting on side walls S₇₂₈ and S₇₀₁-S₇₀₅ will runoff and toward an end of side wall S₇₂₈ due in part or in whole togravitational forces. Similarly, for example, as shown in FIGS. 7A and7B, strengthening member 700 includes second recessed portion 735defined by side walls S₇₀₈-S₇₁₁. Internal angles Θ_(i703), Θ_(i704),Θ_(i705), and Θ_(i706) are obtuse, and external angles Θ_(e704),Θ_(e705), and Θ_(e706) are obtuse. As a result, side walls S₇₀₇-S₇₁₂ aresloped/angled side wall in such a manner that fluid impinging orcollecting on side walls S₇₀₇-S₇₁₂ will run off and toward an end ofside wall S₇₁₂ due in part or in whole to gravitational forces. Alsoincluded are a third recessed portion 736 defined by side wallsS₇₁₅-S₇₁₈; and a fourth recessed portion 737 defined by side wallsS₇₂₂-S₇₂₅.

Recessed portions 734-737 are relatively shallow. Recessed areas havingreduced depths, such as those of strengthening member 700, can beadvantageous other when vehicle components, such as electriccables/wires, fuel lines/pipes, brake lines/wires, and seatbelts, needto be run through or installed inside the internal space of astrengthening member.

Top and perspective views of an alternative exemplary embodiment of astrengthening member 800 having the twenty-eight-cornered cross-section,with sixteen internal angles and twelve external angles, are illustratedin FIGS. 8A-8B, respectively. Similar to strengthening member 700, eachof the internal angles Θ_(i801)-Θ_(i816) and each of the external anglesΘ_(e801)-Θ_(e812) of strengthening member 800 are obtuse. The lengths ofthe sidewalls have been selected such that recessed areas 834-837 have adepth δ₈₃₄-δ₈₃₇, respectively, which is increased in comparison to therecessed areas shown in the strengthening members illustrated in FIGS.7A-7B. Thus, strengthening member 800 provides an exemplary embodimentof a strengthening member in accordance with the present invention thatcan promote moisture shedding and also provide more space around theexterior of the strengthening member in which other vehicle componentsmay be permanently, temporarily or periodically fitted, located, orotherwise disposed.

More generally, the various exemplary embodiments of the presentteachings contemplate, for example, strengthening members with cornershaving different bend radii, with non-uniform cross sections, havingnon-symmetrical shapes, with sides having variable thicknesses, and/orhaving variable tapered sides. Various additional exemplary embodimentscontemplate strengthening members that are bent and/or curved. Moreover,to further adjust a member's folding pattern and/or peak load capacity,various additional exemplary embodiments also contemplate strengtheningmembers having trigger holes, flanges, and/or convolutions as would beunderstood by those of ordinary skill in the art. Combinations of one ormore of the above described variations are also contemplated.

As discussed and embodied herein, the cross-sectional lengths L₁-L₂₈ andthicknesses T₁-T₂₈ of the sides of the strengthening member are tunableparameters of the strengthening member. The cross-sectional lengthsL₁-L₂₈ and thicknesses T₁-T₂₈ of the sides may be tuned to providedesired characteristics in the strengthening member. For example, in theembodiment of FIGS. 3A-3B, these parameters are tuned to provide astrengthening member 300 with side walls and corners that are taperedalong the longitudinal length of the strengthening member 300.

As discussed and embodied herein, the aspect ratio of a cross section ofthe strengthening member is a tunable parameter in accordance with thepresent teachings. The aspect ratio of a cross section of astrengthening member may be tuned to provide desired characteristics inthe strengthening member. For example, in the embodiment of FIGS. 4A-4B,these parameters are tuned to provide a strengthening member 400 havingtwo cross-sectional dimensions along perpendicularly oriented transverseaxes that are substantially different in length the longitudinal lengthof the strengthening member 400.

As discussed and embodied herein, the cross sectional lengths L₁-L₂₈ ofthe sides S₁-S₂₈ of the cross section is a tunable parameter inaccordance with the present teachings. The lengths L₁-L₂₈ of the sidesS₁-S₂₈ of a strengthening member may be tuned to provide desiredcharacteristics in the strengthening member. For example, in theembodiment of FIGS. 5A-5B this parameter is tuned to provide astrengthening member 500 with recess areas 534-537 having particulardepths δ₅₃₄-δ₅₃₇ that extend along the longitudinal length of thestrengthening member 500.

As discussed and embodied herein, the sixteen internal anglesΘ_(i1)-Θ_(i16) and twelve external angles Θ_(e1)-Θ_(e12) are tunableparameters of the strengthening member. The internal anglesΘ_(i1)-Θ_(i16) and external angles Θ_(e1)-Θ_(e12) may be tuned toprovide desired characteristics in the strengthening member. Forexample, in the embodiment of FIGS. 6A-6B, these parameters are tuned toprovide a strengthening member 600 with recessed areas 634-637 having aparticular depths δ₆₃₄-δ₆₃₇ that extend along the longitudinal length ofthe strengthening member 600. Additionally, internal anglesΘ_(i1)-Θ_(i16) and external angles Θ_(e1)-Θ_(e12) may be tuned topromote moisture shedding, as demonstrated in the embodiments of FIGS.7A-7B and 8A-8B.

As discussed and embodied herein, multiple tunable parameters-includingbut not limited to the cross-sectional lengths L₁-L₂₈ and thicknessesT₁-T₂₈ of the sides of the strengthening member, the aspect ratio of across-section of the strengthening member, the internal anglesΘ_(i1)-Θ_(i16) and external angles Θ_(e1)-Θ_(e12) of the corners, andthe depths of the recess areas—may all be tuned within the samestrengthening member. These parameters all may be tuned within the samestrengthening member to provide desired characteristics in thestrengthening member.

In the illustrated embodiments of FIGS. 2A-8B, the strengthening membersmay have a one-piece construction. As stated above, the one-piececonstructions shown in FIGS. 2A through 8B are exemplary only and thepresent teachings contemplate strengthening members of otherconstructions such as two-piece construction or having three or morepieces.

To demonstrate the improved strength and performance features of atwenty-eight-cornered cross-section having sixteen internal angles andtwelve external angles in accordance with the present teachings, theinventors compared various existing and conventional strengtheningmember cross section designs to cross-sections based on the designsdisclosed herein. Exemplary strengthening members were modeled and crashsimulation runs were conducted, as shown and described below withreference to FIGS. 9-13.

Strengthening members of varying shapes (i.e., cross-sections) havingthe same mass, thickness, and longitudinal length were modeled asillustrated in FIG. 9. Crash simulations were then run for each memberto simulate an impact with the same rigid mass (e.g., an impactor),impact speed, and initial kinetic energy.

FIG. 10 shows cross members which have undergone a simulatedquasi-static crush. During each quasi-static crush the impact speed isslow (e.g., 1 in/min). An impactor compresses the members with acontrolled displacement. Therefore, all members reach the same crushdistance with the same crush time. Thus, subjecting multiplestrengthening members to a quasi-static crush provides a comparison ofthe folding length and the crush stability of the strengthening members.As shown in FIG. 10, the twenty-eight-cornered cross-section inaccordance with the present teachings demonstrated stable andprogressive axial collapse, as well as the smallest folding length.

FIG. 11 shows strengthening members which have undergone a simulateddynamic crush. During each dynamic crush, the impactor is propelled by agas gun with a designated mass and initial impact velocity which createsa designated initial kinetic energy. The initial kinetic energy crushesthe members. Performance of each strengthening member can be compared bymeasuring the crush distance and specific energy absorption of eachstrengthening member. As shown in FIG. 11, the twenty-eight-corneredcross-section in accordance with the present teachings also demonstratedthe shortest crush distance.

FIG. 12 illustrates the dynamic crush force (in kN) and associated axialcrush distance (in mm) for the simulated dynamic crush, exerted axiallyon the exemplary strengthening members shown in FIG. 9. As shown in FIG.12, the strengthening member having a twenty-eight-corneredcross-section could sustain a much higher crushing force for a givenresulting crushing distance as compared with the square, hexagonal,circular, octagonal, and twelve-cornered cross-sections. Specifically,the twenty-eight-cornered cross-section in accordance with the presentteachings achieved about a 97% increase in averaged crush force and/orcrash energy absorption as compared with the octagon.

FIG. 13 illustrates the dynamic axial crush energy (in kN-mm) andassociated axial crush distance (in mm) for a simulated dynamic crushexerted on the exemplary strengthening members shown in FIG. 9. As shownin FIG. 13, the strengthening member having a twenty-eight-corneredcross-section could absorb the same total kinetic energy of the impactover a much shorter distance as compared with the square, hexagonal,circular and octagonal cross sections. In particular, atwenty-eight-cornered cross section in accordance with the presentteachings absorbed the full axial crush energy in about 51% of the axialcrush distance as the basic octagonal cross section.

Twenty-eight-cornered cross-sections in accordance with the presentteachings may, therefore, allow improved impact energy management over,for example, basic polygonal strengthening member cross sections, byminimizing mass per unit length, thereby providing mass saving solutionsthat reduce vehicle weight and meet new corporate average fuel economy(CAFE) and emission standards.

Beyond the increased load carrying and energy absorption efficiency,strengthening members in accordance with the present teachings mayprovide additional advantages or benefits such as improved moistureshedding abilities (as noted above), increased bending energy absorptioncapacity, improved manufacturing feasibility, and better fitting of theshape amongst the other components of the complete device (e.g.,vehicle, as noted above).

In addition, a twenty-eight-cornered strengthening member in accordancewith the present teachings also may be tuned to accommodate uniquepackaging requirements for use in various vehicles. By virtue of theparticular shape of the cross section of at least some of thetwenty-eight-cornered strengthening members, it may be easier to couple,bond, attach, or otherwise affix other device components to thestrengthening member. Other device components can include, but are notlimited to, engine mounts or transmission mounts.

Twenty-eight-cornered strengthening members in accordance with thepresent teachings are contemplated for use as structural members in anumber of environments. For example, in a motor vehicle, a strengtheningmember as disclosed herein may be used, for example, as one or more ofcrush cans, front rails, mid-rails, rear rails, side rails, shotguns,cross members, roof structures, beltline tubes, door beams, pillars,internal reinforcements, and other components that can benefit fromincreased crash energy absorption or the other advantages describedherein. In addition, the present teachings can be applied to bothbody-on-frame and unitized vehicles, or other types of structures.

For example, as shown in FIGS. 14 and 15, twenty-eight-corneredstrengthening members with sixteen internal angles and twelve externalangles in accordance with the present disclosure can be a part of orwithin a vehicle frame and/or a vehicle upper body. FIG. 14 illustratesan exemplary embodiment of a vehicle frame 1400 with several componentsfor which the strengthening can be used. For example, the strengtheningmembers in accordance with the present disclosure may form or be used asa part of a front horn 1402, a front rail 1404, a front side rail 1406,a rear side rail 1408, a rear rail 1410, and/or as one or more crossmembers 1412. Likewise, FIG. 15 illustrates an exemplary embodiment of avehicle upper body 1500 with several components for which thestrengthening can be used. For example, the strengthening members inaccordance with the present disclosure may be formed or be used as apart of a shotgun 1502, a hinge-pillar 1504, an A-pillar 1506, aB-pillar 1508, a C-pillar 1510, one or more door beams 1512, a cross carbeam 1514, a front header 1516, a rear header 1518, a cow top 1520, aroof rail 1522, a lateral roof bow 1524, longitudinal roof bow 1526, oneor more body cross members 1528, and/or a body cross member 1530.

Moreover, the strengthening members in accordance with the presentdisclosure may be used as, or form a part of, a vehicle underbodycomponent, for example, a rocker and/or one or more underbody crossmembers. Also, the strengthening members in accordance with the presentdisclosure may be used as or form a part of vehicle engine compartmentcomponents, for example, as one or more engine compartment crossmembers.

Depending on the application, embodiments of the present teachings willhave varied shapes (i.e. various cross-sections) to accommodate specificmember space constraints. When used as a vehicle front rail, forexample, to achieve optimized axial crush performance, the lengths andthicknesses of the sides and/or angles of the corners can all beadjusted (tuned) to provide optimal strength, size and shape to meetengine compartment constraints.

Although various exemplary embodiments described herein have beendescribed as configured to be used with automotive vehicles, it isenvisioned that the various strengthening members in accordance with thepresent teachings may be configured for use with other types of vehicles(e.g. aircrafts, spacecrafts and watercrafts) and/or structures, forwhich it may be desirable to provide increased crash energy absorption.Thus, it will be appreciated by those of ordinary skill in the arthaving the benefit of this disclosure that the present teachings providestrengthening members for various applications. Further modificationsand alternative embodiments of various aspects of the present teachingswill be apparent to those skilled in the art in view of thisdescription.

It is to be understood that the particular examples and embodiments setforth herein are non-limiting, and modifications to structure,dimensions, materials, and methodologies may be made without departingfrom the scope of the present teachings.

In particular, those skilled in the art will appreciate that astrengthening member may include more than one longitudinal section orportion, with each section or portion having one or more of thevariations taught in accordance with the present disclosure. Saidvariation(s) can be made continuously or intermittently along the lengthof each longitudinal section. In other words, strengthening members thatembody combinations of one or more of the above variations to thedisclosed tunable parameters, which have not been illustrated orexplicitly described, are also contemplated.

For the purposes of this specification and appended claims, unlessotherwise indicated, all numbers expressing quantities, percentages orproportions, and other numerical values used in the specification andclaims, are to be understood as being modified in all instances by theterm “about.” Accordingly, unless indicated to the contrary, thenumerical parameters set forth in the written description and claims areapproximations that may vary depending upon the desired propertiessought to be obtained by the present invention. At the very least, andnot as an attempt to limit the application of the doctrine ofequivalents to the scope of the claims, each numerical parameter shouldat least be construed in light of the number of reported significantdigits and by applying ordinary rounding techniques.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the present teachings are approximations, thenumerical values set forth in the specific examples are reported asprecisely as possible. Any numerical value, however, inherently containscertain errors necessarily resulting from the standard deviation foundin their respective testing measurements. Moreover, all ranges disclosedherein are to be understood to encompass any and all sub-ranges subsumedtherein.

It is noted that, as used in this specification and the appended claims,the singular forms “a,” “an,” and “the,” include plural referents unlessexpressly and unequivocally limited to one referent. As used herein, theterm “include” and its grammatical variants are intended to benon-limiting, such that recitation of items in a list is not to theexclusion of other like items that can be substituted or added to thelisted items.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the devices and methods ofthe present disclosure without departing from the scope of itsteachings. Other embodiments of the disclosure will be apparent to thoseskilled in the art from consideration of the specification and practiceof the teachings disclosed herein. It is intended that the specificationand embodiment described herein be considered as exemplary only.

What is claimed is:
 1. A strengthening member for a motor vehicle,comprising a cross section consisting essentially of twenty-eightcorners including sides arranged to create sixteen internal angles andtwelve external angles.
 2. The strengthening member of claim 1, whereineach internal angle ranges between about 30 degrees and about 175degrees.
 3. The strengthening member of claim 1, wherein each externalangle ranges between about 45 degrees and about 175 degrees.
 4. Thestrengthening member of claim 1, wherein: eight of the sixteen internalangles are substantially equal to one another; and the other eight ofthe sixteen internal angles are substantially equal to one another. 5.The strengthening member of claim 1, wherein: eight of the twelveexternal angles are substantially equal to one another; and the otherfour of the twelve external angles are substantially equal to oneanother.
 6. The strengthening member of claim 1, wherein thestrengthening member further comprises at least one recessed portionextending along a length of the strengthening member.
 7. Thestrengthening member of claim 6, wherein the at least one recessedportion is defined by two internal angles and three external angles ofthe strengthening member.
 8. The strengthening member of claim 7,wherein the two of the internal angles defining the recessed portion areequal to one another.
 9. The strengthening member of claim 8, whereintwo of the three external angles defining the recessed portion are equalto one another.
 10. The strengthening member of claim 8, wherein each ofthe two internal angles is obtuse and each of the three external anglesis obtuse.
 11. The strengthening member of claim 6, wherein the at leastone recessed portion is defined by four sides of the strengtheningmember.
 12. The strengthening member of claim 11, wherein the threesides of the strengthening member defining the at least one recessedportion have the same length.
 13. The strengthening member of claim 11,wherein two of the three sides of the strengthening member defining theat least one recessed portion have the same length and the other of thethree sides has a different length.
 14. The strengthening member ofclaim 1, wherein the corners of the cross section have substantially thesame thickness as the sides of the cross section.
 15. The strengtheningmember of claim 6, further comprising four recessed areas, wherein eachrecessed area extends along a length of the strengthening member from afirst end of the strengthening member to a second end of thestrengthening member.
 16. A strengthening member for a motor vehicle,comprising a cross section including twenty-eight corners and includingtwenty-eight sides arranged to create internal angles and externalangles, wherein the corners of the cross section are defined by anglesthat alternate between four consecutive internal angles and threeconsecutive external angles.
 17. The strengthening member of claim 16further comprising a longitudinal axis, wherein the strengthening membertapers along the longitudinal axis.
 18. The strengthening member ofclaim 16, wherein the cross section has more than two bisecting planesof symmetry.
 19. The strengthening member of claim 18, wherein the crosssection has four bisecting planes of symmetry.
 20. The strengtheningmember of claim 16, wherein at least one internal angle of the crosssection varies along at least a portion of a length of the strengtheningmember.
 21. The strengthening member of claim 16, wherein a thickness ofat least one side of the strengthening member varies along at least aportion of a length of the strengthening member.
 22. A vehiclecomprising: a strengthening member comprising a cross section consistingessentially of twenty-eight corners including sides arranged to createsixteen internal angles and twelve external angles.
 23. The vehicle ofclaim 22, wherein the strengthening member is, or is within, at leastone vehicle structural member selected from the group consisting of: acrush can, a front horn, a front rail, a front side rail, a rear siderail, a rear rail, a frame cross member, a shotgun, a hinge-pillar, anA-pillar, a B-pillar, a C-pillar, a door beam, a cross car beam, a frontheader, a rear header, a cow top, a roof rail, a lateral roof bow,longitudinal roof bow, a body cross member, a back panel cross member, arocker, an underbody cross member, and an engine compartment crossmember.
 24. The vehicle of claim 22, wherein: the strengthening memberfurther comprises at least one recessed portion extending along a lengthof the strengthening member; and a brake line, pipe, electric wire,cable, and/or seatbelt is disposed within the recessed portion.
 25. Astrengthening member for a motor vehicle, comprising: twenty-eightsides; and twenty-eight corners, wherein a cross section of thestrengthening member includes a central portion and four lobe portions,and wherein the cross section has more than two bisecting planes ofsymmetry.